Gas lighter and safety control construction



April 2, 1940. E w; ROBERTS ETAL 2, 1-;95 9Q3 GAS LIGHTER AND-SAFETY CONTROL GQNSTHUCTION Filed, Sept; 3; 1935 4 2 Sheets-shat 1 FIGLI...

l0 i a INVENTORS EARL W- ROBERTS April 2, 1940.

E. W. ROBERTS ET AL GAS LIGHTER AND SAFETY CONTROL CONSTRUCTION 2 Sheets-Sheet 2 Filed Sept. 3, 1935 INVENTORS EARL W-ROBERTS y THOMAS L.FERRALL fiwA TTORNEYS Patented Apr. 2, 1940 uNm-zpv STAT-ES PATENT OFFICE GAS LIGHTER SAFETY CONTROL CONSTRUCTION corporation of Ohio Application September 3, 1935, Serial No. 39,045

lClaim.

The invention relates to gas lighters of that type in which the supply of fuel to the main burner is dependent upon the existence of flame in a lighter which is in operative relation to said 5 burner. It is the primary object of the present invention to obtain a construction in which the pilot is automatically lighted upon the supply of gas thereto and is extinguished when the main burner is not in use. It is a further object to effect this automatic ignition of the pilot by electrical means, and to cut out the current as soon as-the lighting of the main burner is accomplished. Still further it is an object to automatically re-establish electrical current in case the pilot is accidentally extinguished, thereby maintaining the operation of the main burner and avoiding the escape of unignited gas. With these and other objects in view the invention consists in the construction as hereinafter set forth.

In the drawings:

Fig. l is a horizontal section through a portion of a gas range and oven to which our improved lighter and control mechanism is applied;

Fig. 2 is a sectional elevation showing the portions of the mechanism outside of the oven with the electrical connections shown in diagram;

Fig. 3 is a sectional elevation of the pilot thermal motor and associated parts arranged within the oven;

Fig.4 is an elevation viewed from the reverse side of Fig. 3;

Fig. 5 is a horizontal section on line 5-5, Fig. 2;

Fig. 6 is a perspective view of a gas cook and 6 associated electrical switch for controlling the operation of the pilot and the main burner;

Fig. 7 is a longitudinal section through the top shown in Fig. 8;

Figs. 8 and 8A are cross sections on line 8-8 40 of Pig. 7 showing respectively the open and closed position of the cock;

Fig. 9 is an elevation of the visual signal means for indicating when the electrical ignition circuit is closed;

1'18. 10 is a sectional view taken on the line "-40 of Figure l.

The improved lighter and control is applicable to various types of fluid fuel burners but is speciflcally shown as applied to the oven burner of 50 a gas range. As illustrated, A is the oven having the usual hollow wall 3 at the side thereof, separating the same from the portion ofthe range containing the open top burners (not shown). Cisthegassupplymanifold andDi's a cockconll nsctedtothis'manifoldandcontrollingthesup- (c1. its-117.1

ply of gas to the oven burner E and gas pilot F. Associated with the cock D is an electrical switch G which is so mounted that upon theinitial turning of the handle of the cock towards open position the switch will be operated to close an electric circuit. Thus as shown, the switch G has an actuating rocker arm G having a bifurcated end G which is engaged by a pin D extending radially from the stem D of the cock D. The specific construction of the switch is conventional and is therefore not illustrated in detail. The cock D is provided with a main port D which in .the full open position connects the manifold with a conduit H leading to the oven burner E. The cock D is also provided with a port D which in the initial movement of the cock towards open position will connect the manifold with a conduit I leading to the gas pilot F.

To prevent the supplying of gas to the main burner in advance of the lighting of the pilot there is arranged in the conduit H an automatic valve J. This contains the valve disk J which is resiliently pressed towards its seat by the spring J and is unseated by a stem J? actuated by a thermal motor or what is sometimes termed a powerstat. This powerstat comprises a U- shaped member K mounted upon a bracket L secured to the inner wall of the oven and also connected by the tubular extension L with the easing of the valve J so as to hold these parts in rigid relation to each other.

.metal is cut away by a series of apertures K with the effect that the heat of the pilot flame is imparted chiefly to the inner edge portion and by expansion of the same will spread the legs of the U. The free leg K extends into proximity to one arm of a bell crank lever J pivoted on the bracket L, the opposite arm of said lever extending in proximity to the stem J' of the valve J. This arm is provided with an adjustment screw J which bears upon the stem J and provides for the original seating. Thus it will be evident that when the pilot flame is lighted the powerstat will be actuated to unseat the valve disk J' and to permit gas to flow through the valve J in the conduit H to the burner E.

The ignition of the gas of the pilot is accomplished by electrical means, preferably comprising a coiled wire resistor M wound about an inp The U-shaped member K has one leg K thereof rigidly secured sulator supporting rod M. This rod is mounted upon brackets M which in turn are mounted upon bolts M passing through insulator tubes M which extend through the hollow oven wall B. On the outer face of this wall is an insulator plate M and the bolts M are clamped thereto by nuts M which also constitute binding posts for the electrical connections and the arrangement is such that when current is supplied to the resistor M it will be heated to incandescence and will instantly ignite the gas issuing from the pilot. Current for the ignition circuit may be supplied from a plug N connected to a socket of an electrical circuit, said plug being connected by the flexible conductor N to a fitting N From the latter a conductor N from one of the leads extends to the switch G and a conductor N from the other lead extends to one of the binding posts M The other of the binding posts M is connected to a conductor N which leads into the oven and is there connected to one of the terminals of a circuit breaking switch 0. This switch is mounted on an insulator support 0' on the bracket L and has the contact arms 0 and O normally closed. The contact arm 0 is, however, arranged in proximity to an insulator pin 0 on the free leg K of the powerstat so that when this leg is moved outward under the heat of the pilot flame, it will separate the contact 0 from the contact 0 When, however, the pilot is unlighted, these contacts will remain closed and the circuit will be completed through a conductor N which leads to the switch G.

The oven burner E is provided with a trailer arm E leading to the pilot F so that when the latter is lighted, the flame will be propagated to the burner.

With the construction as described, the operation is as follows: When the cock D is in the position indicated in Fig. 8A, the conduits H and I are both disconnected from the manifold C and as shown in Fig. 6, the handle D of the cock is in horizontal position. By turning this handle to the vertical position indicated in dotted lines at D the cock will be turned to the position indicated in Fig. 8 and at the same time the switch G will be operated to close the electrical circuit. This will energize the resistor coil M so that the gas flowing through the conduit I to the pilot F and issuing from the latter will be instantly ignited. The gas flowing-through the conduit H is, however, intercepted by the valve J which remains closed until the heat from the pilot flame actuates the powerstat, swinging the leg K outward and through the bell crank lever J and stem J unseating the valve disk J. This will permit gas to flow through the conduit H to the burner E from which the trailer arm E extends to the pilot and will be ignited. At the same time that the leg K opens the valve J it will move the insulator pin 0 against the contact 0 separating the same from the contact 0 and thereby breaking the circuit through the resistor M. This condition will be maintained as long as the pilot flame is burning, but should it be accidentally extinguished while the gas is still supplied thereto, re-ignition will automatically occur. This is accomplished by a closing of the contacts 0 and O permitted by the inward movement of the leg K thereby closing the electrical circuit and re-energizing the resistor coil M so as to again light the pilot. Thus two things are accomplished, first, there can be no continued escape of unignited gas from the pilot flame and second, the burner will be maintained in continuous operation until the cock D is manually operated to turn it off.

To show that the apparatus is in operative position, a visual signal is displayed whenever the electrical circuit through the igniter is closed. This signal comprises an electric lamp P which is mounted at a convenient point on the frame of the range and displays its light through a lens P at the front in proximity to the handle D The lamp P is supplied with current through conductors P and P which extend to the binding posts M. Thus whenever the igniter circuit is closed, a branch circuit will be established through the conductors P and P which will illuminate the lamp P.

What we claim as our invention is:

In a gas range, a main gas burner, a pilot gas burner for igniting the main burner, a manually operable normally closed valve controlling the supply of gas to the main and pilot burners, an automatically operable normally closed valve intercepting the supply of gas from the manually operable valve to the main burner, a thermal motor operable by the pilot burner to open automatically the intercepting valve, and electric ignition for said pilot burner including an electric igniter in lighting proximity to the pilot burner. a normally open electric switch in circuit with the igniter and adapted to be closed by the manually operable valve when the latter is open, and a normally closed switch in circuit with the igniter and first mentioned switch and adapted when the thermal motor is operated by the pilot burner to be opened automatically by the thermal motor to break the circuit from the first mentioned switch to the igniter.

EARL W. ROBERTS. THOMAS L. FERRALL. 

